I'm getting close to finishing the Garn. We will run 1" pex tomorrow. Here's my question. Did anyone use a mixing valve? If so, what specific brand unit/model number did you use? I'd like to mix the supply water down from around 190 degrees at the Garn to about 140 degrees. I plan to use the return water to mix with the supply water. At this point, I have no idea what my return water temp will be. I'm guessing it will still be over 100 degrees (a complete guess). I'm planning on a three way valve that would be hooked up with either 1 1/2" or 2" threaded black pipe. If you mixed your supply down by using your return water, then please tell me how you did it and what mixing valve you used. So far I've got quotes for $600 and $800. That just sounds really steep. The setup is for a forced air furnace, with three separate zones. I'll also be heating DHW. Thanks for the input.